checkip.amazonaws.com/ HTTP/1.1

[tangor]

This is a request, first time I've seen it in the logs. Anyone know what this is? Or why?

GET http://checkip.amazonaws.com/ HTTP/1.1

My server is throwing a 406 on the request. The UA is

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.149 Safari/537.36

[edited by: not2easy at 10:04 am (utc) on May 9, 2020]
[edit reason] readability [/edit]

[not2easy]

A 406 response means that the requested file exists but cannot be used because the client system doesn't understand the format that the file is configured for.

Since the request isn't even for a file on your site, shouldn't there be a 404? Or is there some kind of service on your server that uses that remote file for some process? weird.

[lucy24]

:: detour to look up 406 error as I’m pretty sure I’ve never seen it in my life (400 rarely, 408 very rarely) ::

Huh. If they were requesting a file that actually exists, I would hypothesize that they’ve shot themselves in the foot by being so picky with Accept: headers, they’ve excluded the very file they’re asking for ... which, I suppose, is why Accept: headers typically have */* at the end (“If you don’t have any of these, we’ll take whatever you’ve got.”) But even the horse’s mouth [w3.org] says

HTTP/1.1 servers are allowed to return responses which are
not acceptable according to the accept headers sent in the
request. In some cases, this may even be preferable to sending a
406 response. User agents are encouraged to inspect the headers of
an incoming response to determine if it is acceptable.

Is it possible the server is sending a 406 response as a euphemism for something else? I know mine uses 418 (“teapot error”) to distinguish mod_security lockouts from ones set by the site itself.